The correlation of physical forces, by W. R. Grove. 1st American from 4th English ed.--On the interaction of natural forces, by H. L. F. Helmholtz. Tr. by John Tyndall.--Remarks on the forces of inorganic nature, by J. R. Mayer. Tr. by J. [!] C. Foster.--On celestial dynamics, by J. R. Mayer. Tr. by H. Debus.--Remarks on the mechanical equivalent of heat, by J. R. Mayer. Tr. by J. [!] C. Foster.--Some thoughts on the conservation of forces, by Dr. Faraday.--On the connection and equivalence of forces by J. von Liebig.--On the correlation of physical and vital forces, by W. B., Carpenter.